#int   str   bool float
# a=123
# b='123'
# c='c'
# d='3.14'
# e=3.14
# f=3>2
#print(f+1)
g=False
#print(type(str(g)))
s='True'
#print(bool(s))
#print(g+1)
#a=3.6
# print(int(a))
# print(type(str(a)))
# b=True
# c='123'
#
# k=-100
# print(k)

a=3.99999
# print(int(a)) #float--->int
# b=123
# print(float(b)) #int--->float
# c='3.14'
# #print(int(c))#小数点作为特殊符号无法转换
# print(float(c))#str--->float
# d=3.14
# print(str(d))#float--->str
# print('float--->str:',d)

# s='+36'
# print(float(s))
# s='-36'
# print(float(s))
# s=' 36 '
# print(float(s))
# s='3 6 '#中间不能有空格
# print(float(s))
# print(float('Nan'))# nan非数字类型
# print(int()) #默认值0
# print(float()) #默认值0.0




